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<DIV CLASS="navbar"><A HREF="http://vt100.net/"><IMG CLASS="button" SRC="vt100.net-logo.png" ALT="VT100.net" HEIGHT="16" WIDTH="102"></A> VT220 Programmer Reference Manual<TABLE WIDTH="100%">
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<TD ALIGN="LEFT"><A HREF="chapter4.html">Chapter 4</A></TD>
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<CAPTION>Table 4-3 Level 1-Level 2 Compatibility Comparison</CAPTION>
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<TH ALIGN="LEFT">Difference Area</TH>
<TH ALIGN="LEFT">Level 1<BR>(VT100 Mode)</TH>
<TH ALIGN="LEFT">Level 2<BR>(VT200 Mode)</TH>
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<TD>Keyboard</TD>
<TD><P>Sends ASCII only.</P>
<P>Keystrokes that normally send DEC Supplemental Characters transfer nothing. (Interpreted as an error.)</P>
<P>User-defined keys are do not operate.</P>
<P>Special function keys and six editing keys do not operate (except F11, F12, and F13, which send ESC, BS, and LF, respectively).</P></TD>
<TD>Permits full use of VT220 keyboard.</TD>
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<TD>7 or 8 bits</TD>
<TD>The 8th bit of all received characters is set to zero (0).</TD>
<TD>The 8th bit of all received characters is significant.</TD>
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<TD>Character Sets</TD>
<TD>Only ASCII, national replacement characters, and DEC special graphics are available.</TD>
<TD>All VT220 character sets are available.</TD>
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<TD>C1 Control Characters</TD>
<TD>All transmitted C1 controls are forced to S7C1 state and sent as 7-bit escape sequences.</TD>
<TD>&#8211;</TD>
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